After trouble shooting an issue with radiantCMS, I come up a new RailsRunner to address following issues:

1. Failed to detect Rails version when application bundled with Rails like radiantCMS.
use Rails::VERSION::STRING to get rails_ver now
2. Add our own rack handler into RailsRunner, so, no need to patch Rack anymore.

if you include config/boot i think they are arledy loaded if not
it will load newest version of this libs even application runing older rails
(if there is 2 rails version installed in system exemple: 2.3.5 and 2.3.4)